my leaves are curling, is it down to the change in my ph levels!!!!

hey people some of the leaves on my plants have started curling and i think i might know why but im not 100% shore so i would be very thankful if someone could confirm weather or not im right or if the problem is something else completely!!! about 2 weeks ago after each res change the ph in my res would drop dramatically from 5.8 to 4.5 by the following day, i would then up the ph of my res to 5.8 only to find out it dropped back down to 4.5 again the next day and this went on for almost 2 weeks which is why i think some of my leaves have curled coz i think that the dramatic change in the ph levels have some how made my leaves curl!!! i took a couple of pictures of the problem but as ive never added pictures to my messages before im not shore if ive done it right and if i havent i will have them uploaded as soon as i work it out, thanks people for your help and input!!!!!

Either it's too hot for them or magnesium deficiency

Search cannoe-ing leaves and you will find the answer.